Percutaneous coronary intervention(PCI) is one of the standard therapies for acute coronary syndrome. Despite major advances in PCI procedure, impaired myocardial perfusion frequently occurred after primary PCI and resulted in a larger infarct size and increased morbidity and mortality.Reperfusion injury process can be resulted in additional death of cardiomyocytes and it is suggested that oxidative stress is a contributing factor to induce reperfusion injury.During PCI,trauma occurs to the arterial endothelium, causes the activation and aggregation of platelets.